An injector is a part comprising a plurality of injection elements (conventionally 50 to 100) enabling the combustion member to be fed with the propellant(s) necessary for operation thereof, and in such a manner that the propellants mix quickly and completely in order to ensure combustion that is stable and homogeneous.
For engines using cryogenic propellants, it is conventional to use injectors that have coaxial jet injection elements. However, such an injection system is not adapted to all operating conditions. In particular, it rapidly encounters its limits and fails to enable satisfactory results to be obtained whenever it is necessary to achieve high performance while injecting propellant at large flow rates. As a result, there is no hope of achieving significant cost savings using such a system.
U.S. Pat. No. 4,621,492 describes an injection configuration that makes it possible to envisage operating with large flow rates, in particular because it uses injection elements of annular structure enabling two coaxial jets to be formed adjacent to each other. However, the increase in injection flow rate is achieved to the detriment of combustion which is then no longer optimal, and above all the presence of liquid oxygen in the central body of the injection element considerably reduces the safety of the injector while increasing difficulties during development. Furthermore, such a structure does not simplify in any way the presently existing manufacturing problems due to the large number of parts making up an injector.